Non-protein thiols flux to S-nitrosothiols in endothelial cells: an LPS redox signal.
Non-protein thiols flux to S-nitrosothiols in endothelial cells: an LPS redox signal.
复制标题
内皮细胞中非蛋白质硫醇流向 S-亚硝基硫醇：LPS 氧化还原信号。
DOI：
10.1097/00024382-200014020-00021
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
Young,PR
中科院分区：
文献类型：
--
作者：
Rubin,DB;Reznik,G;Weiss,EA;Young,PR
脂多糖(LPS)通过激活血管内皮细胞中的通路，导致细胞存活、增殖或凋亡，从而损伤血管。有人认为，这些结果是当活性氧和氮中间体氧化低分子非蛋白硫醇(NPSH)时决定的，这些低分子非蛋白硫醇(NPSH)是细胞内主要的还原剂，如谷胱甘肽(GSH)和半胱氨酸(Cys)。NPSHs的氧化还原可能是一个重要的氧化还原信号，如果它被证明发生在损伤后迅速。为此目的，培养的牛主动脉内皮细胞被硫醇荧光探针单溴联氨(MBB)染色。酸可提取的MBB活性加合物主要为GSH(~90%)和Cys(~90%)。在脂多糖暴露的1分钟内，50%-70%的MBB反应性NPSH被消耗，而没有证据表明伴随的超氧化物、过氧化氢、单线态氧或谷胱甘肽二硫化物(GSSG)的净生成。虽然脂多糖诱导了硫醇-二硫键交换速率的增加，但轻微的增加并不能解释NPSH的消耗程度。在从脂多糖暴露中恢复的前10分钟内，MBB反应性NPSH荧光恢复到或略高于基线水平。当在酸提取物中加入氯化汞时，每消耗一摩尔的MBB反应性NPSH，就有一摩尔的S-亚硫醇氧化当量。据推测，MBB反应性NPSH和Hg2+诱导氧化剂的快速流动反映了GSH向GSNO(S亚硝基谷胱甘肽)的转变，可能是内皮细胞暴露于内毒素后的一个重要的氧化还原信号。
mdash;: Lipopolysaccharide (LPS) injures blood vessels by activating pathways in the endothelium that lead either to cell survival and proliferation or apoptosis. It has been suggested that these outcomes are determined when reactive oxygen and nitrogen intermediates oxidize low molecular weight non-protein thiols (NPSHs) such as glutathione (GSH) and cysteine (Cys), which serve as major intracellular reducing agents. The oxidoreduction of NPSHs could be an important redox signal if it were shown to occur rapidly following injury. Towards that end, cultured bovine aortic endothelial cells were stained with the thiol fluorescent probe, monobromobimane (MBB). Most of the acid extractable MBB-reactive adducts are GSH (~ 90%) and Cys (~ 90%). Within 1 min of LPS exposure, 50-70% of the MBB-reactive NPSHs are consumed without evidence for concomitant net generation of superoxide, hydrogen peroxide, singlet oxygen, or glutathione disulfide (GSSG). Although LPS induces an increased rate of thiol-disulfide exchange, the slight increase does not explain the magnitude of NPSH consumption. Within the first 10 min of recovery from LPS exposure, the MBB-reactive NPSH fluorescence returns at or slightly above baseline values. When HgCI2 was added to the acid extract, one mole of S-nitrosothiol oxidizing equivalent was found for every mole of MBB-reactive NPSH consumed. It is suspected that the rapid flux of MBB-reactive NPSHs and Hg2+-inducible oxidants reflects transition of GSH to GSNO (S-nitrosoglutathione) and could be an important redox signal in endothelial cells exposed to LPS.